One year, in an effort to do something different I decided to "blow myself up" on stage.
I wrote a comedy monologue for which I played a character called Winston Smallpiece, a militant immigrant trying to overcome racism to become a member of the Sports Club. (It was never actually a problem!)
I was dressed in a loose-fitting suit, which I made specially out of a pair of old curtains, to hide the blow-up airbed wrapped around my middle. The airbed was connected by a flexible pipe to a pump concealed behind me on stage and controlled by a switch in my hand. As usual I told no one what my act involved. It was to be a complete surprise to audience and cast alike.
I came on stage through a narrow door in the scenery at the back and began my act. After a while, in full flow, I activated the airpump and started to blow up like a balloon.
Two unexpected things happened! Firstly, the sound technicians only six feet away at the side of the stage were thrown into a panic by a strange buzzing (the airpump) in their "cans" and started frantically trying to trace the problem before the whole system went down!
And secondly, when I finished my act and, amid tumultuous applause, turned to exit stage rear, I found I was too big to get back through the door and got stuck halfway!!
This turned into a sort of encore as several stage hands came and struggled to shove me out!! 
